George Leo Haydock

Beware of dogs. [1] The Jews called so the Gentiles; and St. Paul now applies it to those among the Jews who spread false doctrine, who privately snarled and publicly barked against the true apostles. None deserve sharp reprehension more than heretical preachers. — Beware of the concision, or as some French translations, of false circumcision. St. Paul by derision makes use of this word, which signifies a cutting to pieces, or destruction. (Witham)